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Monday, November 16, 2009

Then there was concrete...

I went in to work early, in the hopes of leaving early and getting to take photos of the progress. That strategy failed miserably! I apologize, the photos today were taken late in the day, under an overcast sky, with no tripod, so they turned out rather blurry. If we don't get rain tomorrow, I think I will try to take some better pictures. However, I know if I don't post tonight, I will be getting some email asking how things are going :-)

Marcus hasn't been out to the property in a while, and I was showing him where the property line heads into the woods. You can see in the background, where the dirt piles have been re-arranged, knocked down, and packed.

Here is the garage corner. The footer needs to be down low enough to prevent frost getting under it, and heaving it, and damaging it. Toward the top, you can see where the footer for the north wall steps up. That wall, will be well below the final grade, and so the footer does not need to be lowered to escape frost. The frost line on that wall will be well above the level of the floor. In fact when we are done, that frost line should be above my head when I am inside.

Here you can see how the footer goes up and down as the levels of the ground around the home will be different. The footer under the center wall, starting at the lower left corner, and headed toward the top center, shifts up once it gets past the garage floor. The footer at the bottom shifts up as it goes behind the berm that will be on the southwest corner, and shifts back down as it gets to where the front wall will be exposed for windows and doors. At the top of the photo, you can see where the footer goes back up as it gets behind the berm that will wrap around the south side from the east side of the home.

Here is a better picture of the southwest corner. I'll have to ask Newt about the fact that the concrete isn't continuous. I had expected that the jogs up and down, would involve thicker concrete extending from the lower level of the footer up to the higher level.

Here is the view from the northeast corner. Directly in front of me is where the family room will be.

Something that is missing from this footer, that you would normally see, is the re-bar to connect into the walls that will be poured on top of it. In this case, we decided that drilling holes and putting the rebar in epoxy after the footer sets, would allow better alignment in the re-bar. With a typical framed home, you have a concern of severe wind trying to pull a house off its foundation, and so often times threaded rods are inserted into the wet concrete, and the bottom board in the walls (or sill plate), is bolted down to this. In this house, we will have so many tons of weight, and it will be so well sheltered from the wind that uplift is not a concern. The only concern is providing a link between the footing and walls, to prevent the earth from pushing the walls out of alignment on top of the footings.

By my estimate we used about 11 1/3 cubic yards of concrete for the footers. From the widely varying estimates on concrete density I found, that is somewhere between 11 and 22 tons just for my footers. I guess I don't have to worry about that blowing away :-) Just for fun, I will have to ask Newt how much concrete they actually delivered today.